02 January 2004

Many Worlds Apart

Be kind to people. Don't steal from them. Be honest. The world was created six thousand years ago.

To keep me on track in pursuit of the moral life, I often
sketch out the tenets of my religious beliefs. These elements seem
coherent, although I admit to being a little leery about one of them. It
is, of course, the one about being honest. I feel intuitively that God
would want me to tell old friends they still look good after all these
years. I really need to explore further the theology of honesty.

I didn't always believe all these things. Take the matter of
the world's genesis, for example. In darker days, I thought of myself as
a weak anthropicist. The adjective 'weak' doesn't apply to the
degree of my commitment, but reflects someone's notion that the
principle in which I believed - the weak anthropic principle - is a
weaker variant of another form. Paradoxically, it was for me the weak
version of the principle that was by far the more powerful and
compelling. Attaching to it the epithet "weak", I suspect, is in the
same spirit of banks and insurance companies issuing "nondisclosure
statements"; that is, they are titled antithetically to content in order
to allay any fuss. The strong anthropic principle has it that the
universe must possess properties that ensure the emergence of observers.
This idea always struck me as having unnecessarily strong teleological
overtones. The weak, yet, in my opinion, more powerful version of the
principle is that any observed universe must have those properties
necessary to produce observers. The reason that this principle is so
powerful is that it lacks any of those attributes that expose it to the
possibility of being wrong. It has the incontrovertible and awesome
power of tautology. Anyhow, strong or weak, the anthropic principle is
often proffered as the reason that the universe is seemingly fine-tuned -
that is, all the physical laws and constants of nature are calibrated just-so - to produce galaxies, stars, atomic matter, and, ultimately, life.

For the weak anthropic principle to make sense as an
explanation of fine-tuning, we must accept the notion that there exist
many universes, most of them untuned and lifeless, but in which the
fine-tuning issue would never be raised. Yet - and here's the point -
some tiny fraction of these universes; that is, those in which the laws
and physical constants are just right, would be life-bearing. We could
then conclude, with compelling obviousness, that we must live in one of
the few that are just right for us. So, if someone marvels, somewhat
parochially, that had the fundamental constants of nature been just a
few percentage points different, it would have resulted in chaos and
black holes instead of structure and life, then we can inform them with
confidence that there are indeed plenty of universes just like that, but
it isn’t our problem.

Now, some might ask if there is really any economy of belief in
accepting this multitude of universes in preference to, say, the idea
of a single cosmic designer who went out of his way to do all that
fine-tuning? Perhaps it's just my frugal, north-of-England upbringing,
but, as a general principle, I've always considered vast numbers of
universes to be a rather extravagant solution to any problem. Now to be
fair, one can go some way toward putting these universes on a reasonably
sound physical footing. There is the so-called Everett 'many-worlds'
interpretation of quantum mechanics that has the universe splitting
continually as quantum mechanical wave functions collapse - where each
outcome to a quantum uncertainty represents a branch in the split. On
the other hand, all these branching universes are governed by the same
physical laws, and so this model is of limited help with the fine-tuning
question. Then again, the Everett model doesn't have the monopoly on
multi-universe concepts. There's always the idea that there are multiple
parallel universes with different sets of physical laws -
perhaps even some without much in the way of laws at all, where a
physicist would be hard-pressed to get one lousy paper out of the whole
thing. Or, if arguing for the notion of 'parallel universes' makes you
feel a little nerdish and Trekkie-esque, what about the idea of an
ongoing cycle of big-bangs and big-crunches giving rise to serial
universes? This, of course, raises the issue of geese, as I will
explain.

Say I inform you of the existence of an invisible and generally
undetectable goose in the middle of my desk. What’s the risk of having
you falsify my assertion? I think I'm pretty safe on the science front
because science is quite ill-equipped to take on this sort of
pronouncement. After all, science's starting point generally involves
detection and measurement, and my goose is quite immune to that type of
thing. Perhaps a philosopher - one of those who deals in metaphysics -
could challenge my proposition. Yet again, he or she, by profession,
might be considered less credible than the goose.

Indeed, science's
preoccupation with observation renders it quite impotent when it comes
to denying or confirming the existence of the undetectable. So,
returning to the universes: if they are in principle unobservable -
which they are generally considered to be (with the possible exception
of the Everett model, which wasn't of much use, anyway) - then this
many-universe outlook could not really be considered a scientific one.
Yet, it seems in some intuitive way to have a meta-scientific flavor to
it, doesn’t it? I must confess that I'm not entirely sure why I think
this. Perhaps it's that science has come to gain some foothold on the
physical universe, and on geese too, for that matter. So, to posit the
existence of the undetectable goose or the unobservable universes has a
sciencey feel to it. This would be in contrast to, say, positing the
existence of God, who could by no means be considered some variant on a
scientifically concrete idea. This is the best rationale I can muster
for my meta-science claim.

I admit that any one of these beliefs - in undetectable
universes, invisible geese, or God - would require somewhat of a leap of
faith. I suppose we must each take our own path - and the option to
which I have come to attach my own faith is God. If I were pressed for
some justification (notwithstanding the whole issue of explanatory
economics, which might simply be a case of cheapness on my part), I
think I might play the logical positivism card to argue that at least
the God in which I believe is, in a way I won’t expound here,
detectable.

Now, it would crush me to think that my beliefs could be
construed as an affront to the faith of others. I would not wish to
offend those whose faith attaches to the notion of multiple universes,
nor to offend the goose cultists for that matter. I will not be accused
of attacking the religions of others. I am, after all, fully aware that
my belief is simply one of faith, and that the physics of the natural
world provides no argument for this preference.

Be kind to people. Don't steal from them. Be honest. The world
was created six thousand years ago. As I think about it more, that last
thing about the world being six thousand years old could be another
problem. I suspect it's probably true — raising the tougher and more
pertinent question of this: true in which universe?

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I'm a Christian and a retired weapons scientist, vocations which have sensitized me to some of the ways in which the world is dangerously insane. So, on 4 July 1996 I founded the Virtual Church of the Blind Chihuahua, which is moving to this blog.